1. Field of the Invention
The present invention relates to a fuel injector and particularly relates to a spark ignited internal combustion engine.
2. Description of the Related Art
In the case of an engine which equipped with a fuel injector in which a needle valve moves in a valve body, when the engine is stopped in a hot condition and restarted before the engine has cooled down, bubbles generated between the valve body and the needle valve are mixed in the fuel, so that it becomes difficult to inject the correct amount of fuel and an insufficient amount of fuel may be injected. Consequently the air-fuel ratio of the intake mixture becomes lean, which cause poor initial firing and excessive exhaust emissions.
Therefore, a fuel injector which can move the bubbles in the fuel injector to the delivery line quickly, by enlarging a path for communicating between upstream and downstream sides of a horse-shoe shaped stopper plate, is disclosed in Japanese Unexamined Patent Applications (Kokai) No. 62-70655, National Publication of International Patent Application No. 5-500256 and Japanese Examined Patent Application (Kokoku) No. 1-41828.
However, the above described fuel injector requires increased manufacturing man-hour for machining to enlarge a path for communicating between upstream and downstream sides of the horse-shoe shaped stopper plate.